It may hit 70 degrees out on Sunday if the predictions of the weather stations bear out. If not this weekend, however, it is coming. Temperatures are going to progressively rise until 70 degrees is a cooler day amid days in the 80s, 90s and, hopefully not too many, in the 100s.

When temperatures hit the 70s, you can generally roll the windows down and the fresh air is temperate enough to keep you comfortable, as long as the wind coming in the windows doesn’t bother you. On days when the temperature rises into the 80s, 90s and above, it’s really time to roll up the windows and turn on the air conditioning.

Wouldn’t it be a nasty surprise if you rolled up the windows, turned on the air conditioning and nothing but hot air came out of the vent? Imagine that you have a lot of running around to do, you have your 2-yard old in the car seat in back and it feels like a blast furnace coming out of the vents. Your only choice, at that moment, is to turn off the air conditioning, roll the windows back down and grin and bear it.

Hopefully, the 2-year old will understand. There’s a good chance that won’t be the case, though. Why would they understand?

On that day when you discover the air conditioning in your car doesn’t work you’ll want to make an appointment with an auto repair shop to fix your air conditioning. Of course, on those first dog days of summer, you’re probably not the only person who will discover that their car’s air conditioning doesn’t work. The auto repair shop you trust is liable to have a lot of calls to fix the air conditioning in peoples’ cars. You may find that you can’t get your car in right away. And all the auto repair shops are dealing with the same crush of those who need the air conditioning fixed in their cars.

The way to avoid the unpleasant surprise, on a hot summer day, that you air conditioning doesn’t work is to make sure it does work. This is good logic for your car and your home. And, in both cases, by applying an ounce of prevention, you’ll avoid getting caught in the rush to have air conditioning systems fixed while the heat is bearing down on us.

The solution, therefore, is to schedule to bring your car in and have the air conditioning checked when we’re hoping the temperature will climb into the 70s for a change.

There’s a good chance, even if your car’s air conditioning is working properly, you’ll need to recharge the system. This is important because, sometimes, it’s not that the air conditioning doesn’t work; it’s that the air conditioning just can’t seem to keep up with the heat.

The moral of the story is to have your air conditioning checked before you need it so you can concentrate on enjoying the summer without sweating the big stuff.